Cultivated plants have long been used in the home, office and other buildings in order to beautify the surroundings. More recently, a number of health benefits have been attributed to the presence of household plants. Generally, all household plants must be periodically watered in order to maintain plant growth. The frequency of watering which is required varies with the plant, the soil characteristics and the environment. It is known that one of the principal causes of plant death is due to an improper watering regime resulting from inadequate or excessive watering.
European patent number 87-074115/11 describes a plant cover roofing which collects water and supplies it to underlying plants in a controlled manner. U.S. Pat. No. 5,020,261, entitled, "MOISTURE SENSITIVE SELF-WATERING PLANTER" discloses a moisture sensitive self-watering planter having a control valve that controls the flow of water to the plant. The control valve is actuated in response to a decrease in the weight of the soil as the soil loses moisture. U.S. Pat. No. 5,351,437, entitled "MOISTURE SENSITIVE IRRIGATION CONTROL SYSTEM," discloses a similar weight-based control system for actuating a water valve. None of these prior art patents discloses an automatic plant watering device as provided by the present invention.